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Low pressure casting process is a casting method between pressure casting and gravity casting, its basic principle is in the holding furnace with metal liquid, pass dry compressed air, acting on the surface of the metal liquid to maintain a certain temperature, so that the metal liquid along the liquid lift tube from the bottom up, through the sprue into the sand cavity, to increase the pressure after the metal liquid filled the cavity, and keep the gas pressure on the liquid surface until the casting is completely Then the pressure is lifted and the unconsolidated liquid metal in the riser tube and sprue falls back into the holding furnace to complete a casting process. The desired casting is obtained after opening the box.
Sand low pressure casting equipment consists of two parts: holding furnace and liquid level pressurization control system. The furnace cover is used as the working platform of the sand box, and the sand box is fixed directly on the furnace cover for pressurization and pouring.
The operation process is as follows: the operator will make a good type, close the sand box lifting on the working platform of the holding furnace, and realize the docking and sealing with the liquid-raising pipe mouth, and then start the pressurized pouring, to realize the automatic pouring of liquid-raising, filling, pressurization, pressure-holding, pressure-unloading and other casting pressurization process, and then lift the sand box off the working platform and open the box to take the parts.
The liquid surface pressurizing device adopts imported proportional valve + high precision pressure sensor to realize the detection and real-time closed-loop feedback control of the pressure in the holding furnace, PID adjustment mode. With multi-stage linear pressurization, automatic tracking set pressurization process curve, insulation furnace leakage compensation, liquid level compensation and other functions. High accuracy of pressure control and good repeatability ensure stable consistency of low-pressure pouring process. Especially for sand low-pressure casting, which is prone to scouring and sand staining of the cavity by metal liquid, sand low-pressure casting requires high performance of the liquid surface pressurization control system, which must completely eliminate the jittering phenomenon of liquid surface in the process of filling, the filling must be smooth, the filling rate must be constant, the pressure control must be accurate, and ensure the accurate reproducibility of the pressurization process parameters. Only in this way can the casting yield be effectively improved.
The control system adopts computer as the upper monitoring and management computer, running Haomai's self-developed monitoring and management software, with full Chinese standard Windows interface, easy to operate. Adopting database technology, all data of the pressurization process are saved in the database, which can store the actual process data of each casting, and can trace and analyze the historical process data, which can greatly improve the process quality management of production.
Low pressure casting process is a casting method between pressure casting and gravity casting, its basic principle is in the holding furnace with metal liquid, pass dry compressed air, acting on the surface of the metal liquid to maintain a certain temperature, so that the metal liquid along the liquid lift tube from the bottom up, through the sprue into the sand cavity, to increase the pressure after the metal liquid filled the cavity, and keep the gas pressure on the liquid surface until the casting is completely Then the pressure is lifted and the unconsolidated liquid metal in the riser tube and sprue falls back into the holding furnace to complete a casting process. The desired casting is obtained after opening the box.
Sand low pressure casting equipment consists of two parts: holding furnace and liquid level pressurization control system. The furnace cover is used as the working platform of the sand box, and the sand box is fixed directly on the furnace cover for pressurization and pouring.
The operation process is as follows: the operator will make a good type, close the sand box lifting on the working platform of the holding furnace, and realize the docking and sealing with the liquid-raising pipe mouth, and then start the pressurized pouring, to realize the automatic pouring of liquid-raising, filling, pressurization, pressure-holding, pressure-unloading and other casting pressurization process, and then lift the sand box off the working platform and open the box to take the parts.
The liquid surface pressurizing device adopts imported proportional valve + high precision pressure sensor to realize the detection and real-time closed-loop feedback control of the pressure in the holding furnace, PID adjustment mode. With multi-stage linear pressurization, automatic tracking set pressurization process curve, insulation furnace leakage compensation, liquid level compensation and other functions. High accuracy of pressure control and good repeatability ensure stable consistency of low-pressure pouring process. Especially for sand low-pressure casting, which is prone to scouring and sand staining of the cavity by metal liquid, sand low-pressure casting requires high performance of the liquid surface pressurization control system, which must completely eliminate the jittering phenomenon of liquid surface in the process of filling, the filling must be smooth, the filling rate must be constant, the pressure control must be accurate, and ensure the accurate reproducibility of the pressurization process parameters. Only in this way can the casting yield be effectively improved.
The control system adopts computer as the upper monitoring and management computer, running Haomai's self-developed monitoring and management software, with full Chinese standard Windows interface, easy to operate. Adopting database technology, all data of the pressurization process are saved in the database, which can store the actual process data of each casting, and can trace and analyze the historical process data, which can greatly improve the process quality management of production.
